Automobile overspeed warning system

ABSTRACT

An automobile overspeed warning system includes speed sensors for sensing the rate at which an automobile is travelling and speed selectors for receiving an input from the automobile driver indicating a top speed which the driver seeks not to exceed. The overspeed warning system compares the two values and activates an alarm when the desired limit is exceeded. The system can be used in conjunction with an existing cruise control system as a back-up system to warn the driver that the cruise control system has not been reset, or it can be used independently of a cruise control system to prevent the driver of an automobile from unknowingly or inadvertently operating his or her vehicle in excess of a certain speed for safety or other reasons. The system can be provided as a retrofit kit or as an integral part of an existing micro-processor controlled electrical system within the automobile.

This application is a continuation-in-part of U.S. Patent applicationSer. No. 09/123,392, filed Jul. 21, 1998.

FIELD OF THE INVENTION

The present invention relates to an overspeed warning system for anautomobile.

BACKGROUND OF THE INVENTION

When driving a car, it is often desired to maintain a certain rate ofspeed, and yet not to exceed that speed. This is a popular feature, andis commercially available in cars which have a cruise control feature.Cruise control has a number of disadvantages. Cruise control is notuseful in city streets where the traffic is slow, and often accompaniedby frequent stops, and the posted speed limits are low. Cruise controlis not practical on busy highways where the traffic is heavy and thegeneral speed of the traffic may fluctuate from relatively high speedsto very low speeds, or stopped conditions. Cruise control is notrecommended on winding roads where it is not safe to drive at a steadyspeed. Cruise control is not effective on hills where maintaining asteady speed requires the application of the accelerator or the brake.Cruise control can be dangerous on slippery roads where fast changes intire traction can cause needless wheel spinning, and a possible loss ofcontrol of the vehicle. At least one known type of cruise controlautomatically shuts off when the brake is applied and automaticallydisengages when the optional traction control system begins to limitwheel spin. The driver of the vehicle may forget to restart the cruisecontrol afterwards when resuming a high rate of speed, such that the carmay exceed the desired cruising speed without the driver being aware ofit. A driver who forgets or is unaware that the cruise control hasceased to function may find benefit in having an overspeed set at aspeed beyond the desired cruise control speed, to act as a back-upsystem.

Whether or not a car has cruise control, a driver can benefit from anautomobile overspeed warning system. The primary purpose of anautomobile overspeed warning system is to prevent the driver of anautomobile from unknowingly or inadvertently operating his or hervehicle in excess of a certain speed limit for safety or other reasons.This enables the driver to concentrate on the challenges of driving,rather than being distracted by constantly monitoring or watching overthe speed of his or her vehicle. The driver of the vehicle may bemotivated by a desire or need to remain within the posted speed limit,or by a concern or worry for safety under given road or weatherconditions. An automobile overspeed warning system reminds or warns thedriver that it is not safe, or lawful, to operate his or her vehicle inexcess of a certain speed limit in certain circumstances, whether thosecircumstances are due to mechanical, environmental or legal constraints.An automobile overspeed warning system can provide drivers ofautomobiles with valuable peace-of-mind.

In an automobile overspeed warning system, the driver of the vehicle canset or select a speed limit anytime, and when the speed of his or hervehicle exceeds that speed limit, a warning to the driver will follow.

When a person is driving, an unduly harsh warning may be startling, andmay cause an involuntary reaction that could be dangerous to the driverand to others. For that reason a loud or shrill warning would not be thebest solution to the problem. It would be preferable to provide awarning in a gentle, or calming voice, or to use soothing music as awarning that is clearly perceptible to the driver, and yet unlikely tobe startling. A driver receiving such a warning can consider the speedof the car carefully and make appropriate changes without undueabruptness.

It would also be advantageous to have an overspeed warning systemavailable in a kit form that can be retro-fit on existing automobiles.To that end, whether the warning system is entirely electrical, entirelymechanical, or some combination of electrical and mechanical components,it would be advantageous to be able to install those components onexisting automobile hardware without having to undertake anunreasonable, or uneconomic, amount of work.

Accordingly, there is a need for a relatively simple overspeed warningsystem that can be used independently of a cruise control system.

SUMMARY OF THE INVENTION

According to a broad aspect of the invention there is an automobileoverspeed warning system for a passenger car. It comprises a speedsensor for sensing the speed of the automobile; a speed selector onwhich an operator may select a desired speed; a comparator for comparingthe speed sensed by the sensor with the speed selected with theselector; and a warning annunciator connected to the comparator. Theannunciator is connected to annunciate a warning when the speed sensedexceeds the speed selected.

In an additional feature of this aspect of the invention, theannunciator includes at least one of (a) a voice message generator; (b)a musical message generator; and (c) a flashing light. In a furtheradditional feature of that aspect of that invention, the speed sensor ischosen from the set of speed sensors positioned (a) to measure speedfrom the speedometer of the car; (b) to measure the rate of rotation ofa drive shaft of the car; and (c) to measure the rate of rotation of awheel of the car. In a further additional feature of that aspect of theinvention, the selector includes a knob by which the selected speed canbe changed while the car is in motion.

In a still further additional feature of that aspect of the invention,the speed sensor is a magnetic sensor; the comparator includes amicro-processor; and the annunciator includes a loud speaker. In a yetfurther additional feature of that aspect of the invention, theoverspeed warning system is in the form of a retro-fit kit. Furtheragain, in another additional feature of the invention, the overspeedwarning system is combined with a cruise control system. The warningsystem is operable at a selected speed higher than the cruise controlspeed.

In another further additional feature of that aspect of the invention,the warning system includes a display for indicating when the warningsystem is "on". In yet another additional feature of that aspect of theinvention the speed selector includes a knob movable to an "on"position, and the display includes an illumination element forilluminating the knob that is lit when the knob is in the "on" position.In another alternative additional feature of that aspect of theinvention, the comparator comprises a microprocessor connected to sampleinput signals from the speed sensor and from the speed selector. Themicroprocessor is provided with software for comparing these inputsignals, and is connected to provide an output signal to theannunciator.

In another aspect of the invention, there is a method of providing anoverspeed warning to an automobile driver. That method comprises thesteps of providing a speed selector; selecting a speed on the speedselector sensing the vehicle speed; comparing the vehicle speed with theselected speed; and annunciating a warning to the driver when thevehicle speed exceeds the selected speed.

In an additional feature of this other aspect of the invention, themethod includes the steps of providing a cruise control system andselecting a cruise control speed. In a further additional feature ofthat additional feature, the step of selecting a speed on the speedselector includes selecting a higher speed on said speed selector thanthe cruise control speed.

In a further additional feature of that aspect of the invention, thestep of sensing includes one of (a) obtaining a speed signal from thespeedometer of the automobile; (b) measuring the rate of rotation of thedrive shaft; and (c) measuring the rate of rotation of the wheels of theautomobile. In a still further additional feature of that aspect of themethod includes using a programmable micro-processor to compare thevehicle speed and the selected speed.

In a yet further feature of that aspect of the invention, the step ofannunciating includes at least one of (a) playing a recorded message;(b) playing a recorded piece of music; (c) playing a synthesized voicemessage; (d) playing a synthesized musical message; and (e) illuminatinga light. In a still further additional feature of that aspect of theinvention the method includes illuminating a display to indicate to thecar driver that the system is "on".

BRIEF DESCRIPTION OF THE DRAWINGS

For purposes of illustration, but not of limitation, to yield a betterunderstanding of the present invention and to show more clearly how itmay be carried into effect, reference will now be made by way of exampleto the accompanying drawings, which show an apparatus according to thepreferred embodiment of the present invention, and some alternativeembodiments thereto, and in which:

FIG. 1 is a general schematic drawing setting out the conceptualelements of an example of an overspeed warning system embodying theprinciples of the present invention;

FIG. 2 is an example of an algorithm by which the overspeed warningsystem of FIG. 1 operates;

FIG. 3 is an electronic block diagram for an alternative, stand-aloneversion of the overspeed warning system of FIG. 1;

FIG. 4 is a flowchart for the stand-alone warning system of FIG. 3;

FIG. 5 is an electronic block diagram of a simple, integratedalternative version of the overspeed warning system of FIG. 1;

FIG. 6 is a flowchart of the simple, integrated version of FIG. 5; and

FIG. 7 is an electronic block diagram of the warning system of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The description of the invention is best understood by commencing withreference to an embodiment, or embodiments, of the invention as shown inexamples illustrated in the Figures. These examples are given tofacilitate explanation of the invention. The invention is not limited tothe specific embodiments illustrated. Some proportions may have beenexaggerated for the purposes of conceptual illustration.

Referring first to FIG. 1, a car is shown generally as 20. It proceedsalong a road at a given speed, V. It has a standard 12 Volt D.C.electrical power supply system 22 that powers all the electricalcomponents of the vehicle, whether lights, starter, wiper motors, fans,or electronic engine control logic microprocessors. Car 20 has aspeedometer 24 and a speedometer cable 26. Cable 26 is mechanicallyconnected to monitor the speed of car 20, whether by measuring the speedof the output shaft from the transmission 28, the rate at which thewheels turn, or some other suitable indicator. The rate at which theoutput shaft turns is a convenient measure. It is a fixed multiple ofthe rate at which the wheels turn, and hence is directly proportional tothe speed of the car. Both mechanical and electronic speedometer systemsare available.

Car 20 is also shown with a cruise control system 30, although anoverspeed warning system can also be applied to cars that do not havecruise control. Cruise control system 30 is connected to electricalsystem 22, and includes a clock signal generator 32 and a cruise controlmicroprocessor 34. It receives a speed input signal either fromspeedometer 24, speedometer cable 26, from a wheel sensor 36, or fromsome other suitable device, and transmits an output signal to drive afuel flow control 38 for controlling fuel flow through a fuel pump 40 toengine 42. Cruise control system 30 need not depend on any elements ofthe speedometer, whether mechanical or electrical, and could be acompletely independent system. Cruise control system 30 is set byoperating car 20 at a desired speed, that is, the cruise control speed,and then signalling to cruise control microprocessor 34 to record inmemory the setting at that desired speed as a reference. Cruise controlmicroprocessor 34 also receives an interrupt signal from a brake pedalswitch 44. When the brake is operated cruise control system 30 isinterrupted and becomes inactive. Once the driver has ceased to brake heor she may then input a resume signal to cruise control microprocessor34 to cause cruise control system 30 to operate actively again. In duecourse the speed sensed will match the referenced signal in memory.

As shown in FIG. 1, in one embodiment of the invention the overspeedwarning system includes an overspeed warning microprocessor 46. Itreceives power from power supply system 22 and receives a timing signalfrom clock signal generator 32. Alternatively, an independent clocksignal generator could also be used. Overspeed warning microprocessor 46receives input signals either directly, or indirectly as, for example,through cruise control microprocessor 34. One input is a speedmeasurement, either from the output shaft of the transmission, 28, wheelsensor 36, or speedometer 24.

The system also requires that a speed selection be made by the driver.The speed selected can be displayed so that the driver can know, orconfirm, that the speed selection is correct initially, and currentthereafter. Overspeed warning microprocessor 46 receives two types ofinput from a speed selection knob 48. The first input is an "On" or"Off" signal to activate or deactivate the system generally. Forexample, the "On" "Off" function can correspond to a spring loadedbutton in either "Out" or "In" positions. In the preferred embodimentknob 48 is translatable, as by pressing or releasing from a spring load,along an axis of knob 48, between the "On" and "Off" positions, and isrotatable about its axis to select a specific speed. Such a springloaded button, or switch, need not provide a signal to overspeed warningmicroprocessor 46, but could act as a switch in either the power (orground) connection to overspeed warning microprocessor 46. Similarly,knob 48 can alternatively be illuminated by a lighting element 50 whenactivated, the illumination being automatically shut off when car 20 isnot in operation. Knob 48 is mounted in a convenient location that canbe reached by the driver during operation of car 20. The preferredlocation is on the dashboard of the car adjacent to the speedometerdisplay. It could, alternatively, be located on the steering column in aposition similar to that of a turn signal indicator or windshield-wipercontrol arm. Further still, some vehicles have a lower central dashboardconsole that is used to house heating and cooling controls or a radio,CD player or tape player, or both heating and cooling controls and radioand musical entertainment devices. Another alternative mounting locationis in this console, or dashboard region. Further again, a number of carshave a gear shift console located on a raised portion of the floor panlying along the longitudinal centerline of the car. An overspeed warningsystem control could also be mounted in this region.

The second function of speed selection knob 48 is to permit the driverto select a desired overspeed limit value. Once in the "On" position,this selection is made by turning knob 48 clockwise or counter-clockwiseto obtain the desired value. The rotation of knob 48 may operate amechanical linkage, a rheostat, or an analogous device to provide ananalogue signal. This signal can be converted to a digital form andshown on a display 52, preferably an LED, but possibly an LCD or even bya mechanical linkage and gear type display mounted in sight of thedriver, typically on the driver's console, not far from the speedometer.In the event that the system is electronic, an initial default setting,such as 100 km/h can be programmed in and displayed when the system isturned "On" by pushing knob 48 to its "Out" position. Alternatively, themost recently chosen setting can be stored in memory, and can bedisplayed when the system is re-activated.

An output port of overspeed warning microprocessor 46 is connected toactivate a warning annunciator in the nature of an alarm circuit 54having an audible speaker 56 and a visible signal, such as a flashinglight 58. Audible speaker 56 can be an existing audible warning devicein the car such as a door or seat-belt warning buzzer. For example, ahigh voltage output from overspeed warning microprocessor 46 can be usedby alarm circuit 54 to drive a relay driven switch in which power isapplied to the positive side of speaker 56 and flashing light 58. Anumber of possible alternative configurations can be chosen. It is notnecessary to have both audible and visual signals, and if one is chosen,it is preferred that an audible signal be provided. It is preferred thatthe audible signal not be unduly harsh. For that reason, rather than usea buzzer, a synthesized voice signal, or musical signal, can beamplified and directed to speaker 56 instead. Alarm circuit 54 mayalternatively include a tape recorded message, possibly on a loop, or atape recorded piece of music.

The embodiment described can be supplied in a "stand-alone"configuration as a kit available from an automotive supply store forretro-fit to an existing vehicle. It may be that car 20 is of such avintage that it lacks an existing micro-processor that can be adaptedfor this additional purpose, or it may be that the existingmicroprocessor cannot be re-programmed. In that case a stand alonemicroprocessor can be provided, along with suitable elements for sensingand interpreting automobile speed, whether as original equipment or as aretro-fit kit. In the case of a retro-fit kit, although a predominantlyelectronic system is preferred, it is possible to construct a system oflargely mechanical elements for controlling an audible alarm.

Such a stand-alone kit may entail duplication of elements alreadyexisting within the electrical system of car 20. Whether a stand-alonekit is used, or the system is supplied as a factory installation, someduplication can be avoided by using elements of the existing design ofthe car. In the most preferred embodiment, an existing microprocessor incar 20, such as cruise control microprocessor 34, that is provided toperform one or several other functions, is merely provided with anadditional software package containing programming steps to perform thelogic operations set out in the algorithm of FIG. 2, and such additionalmemory space, as may be required. This would obviate the need for asecond, separate microprocessor such as microprocessor 46. Similarly,the use of an existing alarm buzzer or speaker has been noted above. Theuse of a loudspeaker of an existing audio system of the car, such as anexisting speaker of a radio, CD player, or cassette player permits arelatively high quality sound to be used, rather than a harsh buzzer.For example, it permits a voice message or musical message of the sametone and quality as FM radio. When provided with a voice recordingfunction, the system can play a pre-recorded message of the operator'schoosing, or a piece of music of the operator's choosing, or somecombination of a voice message and music, whether sequentially oroverlaid on top of each other to produce a soothing effect.

It is assumed that the existing cruise control system 30 already has acalibrated electronic measurement from which speed can be inferred,whether in analogue or digital form. If in digital form, the signal canbe used directly. If in analogue form, an A-D converter may be required.In any case, this existing speed signal can be used by the additionaloverspeed warning software. Where existing circuitry can be used, only adevice for setting an overspeed limit, such as knob 48 and a displaysuch as display 52, are required.

Whether using an existing microprocessor, or a dedicated microprocessoras indicated in FIG. 1, the logic of operation is similar. In a typicalelectronic system for a car, several functions can be included in asingle microprocessor. FIG. 2 shows an "elaborate-integrated"subroutine. FIG. 7 shows the electronic block diagram of the warningsystem of FIG. 2. The automobile overspeed warning system is anadditional subroutine included with the existing microprocessoroperating instructions of the electronic car system. Such a systemoperates on a continuous basis when the engine is running, such that theoverspeed warning system is subroutine is called repetitively on asubstantially continuous basis, with a time period of, typically, a fewmilliseconds between repetitions. The system has a status register, orflag, that is used to recall the previous status each time thesubroutine is entered. The subroutine returns to the main loop afterprocessing the inputs and adjusting the outputs as required.

Referring to FIG. 2, a "Speed Warn" subroutine starts as indicated atthe top of the page. The first "Status" determines whether the system isactive or inactive according to the axial position of knob 48 ("In" or"Out", corresponding to "Off" and "On"), and sets the memory registeraccordingly. If the system is "Inactive" the subroutine continues to"Return" and the system waits for the next cycle. If the system statusis "Active" then a further check will be made to see if knob 48 hasmoved to the "Off" condition. In that case alarm circuit 54 and LEDdisplay 52 are set to "Off", and the "Status" register is set to"Inactive". If knob 48 is "Out" and the system status is "Active" thenthe "Speed" value derived from monitoring, for example, wheel sensor 36,is compared with the "Limit" register value derived from the angularposition of knob 48. If the "Limit" value is exceeded then the alarmregister will be set to "On" (otherwise to "Off"), resulting in theactivation of alarm circuit 54. In the next decision box, the systemdetermines whether knob 48 has moved. If not, then the subroutineproceeds to "Display" and then to "Return". If knob 48 has turned thenthe value in the "Limit" register will be increased or decreasedaccording to the extent of the clockwise or counter-clockwise rotationof the knob about its axis. In either case the limit value will continueto be displayed. In a stand-alone system this subroutine would runcontinuously as long as knob 48 remained "On". Notably, the angularsetting of knob 48 can be changed at any time. Thus when car 20 turnsfrom one road on to another, and the speed limit or the drivingconditions change, another "Limit" value can be selected while car 20 isin motion. Alternatively, the speed selected with knob 48 can be changedwhile the car is stopped, such as before a journey commences or while ata stop light or stop sign. Then, when the car proceeds out onto the roadthe warning has already been selected by the driver. Inasmuch as themost recently selected speed is stored in memory, knob 48 can be movedto its "Off" position to deactivate system 20 as the driver may desire,and then moved to its "On" position, in which the system will bere-activated to give a warning at the most recently selected speed.

Whether the system is primarily mechanical or electronic, a retro-fitkit can measure vehicle speed in at least three ways. It can measure therotational speed of the wheels, typically with a mechanical countingwheel, an optical sensor, or a magnetic or inductive sensor. Such asensor can be mounted to count wheel rotations directly, or can bemounted to count the number of turns made by the output shaft of thetransmission of the car, or may draw a signal directly from an existingspeedometer cable. With known vehicle geometry the number of turns perminute of either the output shaft, the wheels, or the speedometer can beconverted into actual vehicle speed. For a retro-fit kit, a table ofconversion factors for commonly available makes and models of cars couldbe provided, with the appropriate calibration adjustment factor beingentered into memory on installation.

In all embodiments, a successful retro-fit kit can be assembled from aspeed measuring sensor, a speed selector, a speed selector display, analarm, a microprocessor for comparing the actual speed and the selectedspeed, and appropriate logic circuits or software for performing thatcomparison function.

A rudimentary alternative overspeed warning system is illustratedconceptually in FIGS. 3 and 4. This system is indicated generally as 70and retains power supply system 22, a speed sensor, such as sensor 36,an illumination, such as lighting element 50, and an alarm, such asalarm 54. Alternative system 70 includes an alternative speedcomparator, in the form of microprocessor 72 having an alternativeinstruction set according to the logic of FIG. 4. System 70 includes aset of speed warning buttons, one "warning-on" button 74 and one"warning-off" button 76, in lieu of knob 48 and display 52. When thevehicle has reached a certain speed as per speedometer 24, the driver ofthe vehicle can press the "warning-on" button to arm the system, and atthe same time set the speed limit at that particular speed. Optionally,"warning-on" button 74 can be lit, or a light can be illuminated whenthe system is armed. The system is disarmed when "warning-off" button 76is pressed, and is also be shut off automatically when the ignition ofthe vehicle is turned off When the driver of the vehicle wishes tochange the speed limit, system 70 can be reset anytime by pressing"warning-off" button 76 first, then, when the vehicle has reached thedesired speed, pressing "warning-on" button 74 again to set the newspeed limit at that desired speed.

Similarly, FIG. 5 is an electronic block diagram for, and FIG. 6 is aflowchart of, a simple-integrated version of the same alternative. In atypical electronic car system, several functions can be included in asingle microprocessor. The alternative overspeed warning system 80 ofFIG. 5, whose flowchart is shown in FIG. 6 does not employ a separatemicroprocessor, but uses an existing microprocessor 82 and merelyprovides an overspeed warning subroutine which is called every fewmilliseconds as part of a main processing loop. System 80 retains the"warning on" and "warning off" buttons, 74 and 76, of the embodiment ofFIG. 3 and 4. The remaining elements of this alternative embodimentcorrespond generally to those of the embodiment of FIGS. 1 and 2, andinclude power source 22, clock 32, wheel sensor 36, lighting element 50,and alarm 54. Existing electronic system controls, such as warninglights, seat belt buzzers, engine controls, and other similar devicesthat interact with microprocessor 82 are indicated generally as 84.Similarly, pre-existing electronic system sensors, such as doorswitches, a tachometer, wheel sensors and other similar devices areindicated generally as 86.

In another alternative, the functions of knob 48 could be separated byproviding a distinct "On-Off" switch, and a separate limit calibrationdevice, whether a rotating knob or a set of up-and-down keys by which alimit value may be adjusted incrementally from a datum, or a set ofnumbered keys by which a specific value may be entered.

It is possible to make other embodiments that employ the principles ofthe invention and that fall within its spirit and scope. The descriptionis made for the purpose of explanation, and the invention is not to belimited to the embodiments described but only by the claims which followand by equivalents thereto.

I claim:
 1. An automobile overspeed warning system for a passenger carcomprising:a speed sensor for sensing the speed of the automobile; aspeed selector on which an operator may select a warning speed, saidspeed selector being mountable within reach of the driver of the car,and being operable at any time the motor of the car is running; awarning speed display connected to show the selected warning speed, saidwarning speed display being mountable in a location visible to thedriver of the car; a comparator for comparing the speed sensed by saidsensor with the warning speed selected with said selector; a warningannunciator connected to said comparator to give a warning when thespeed sensed exceeds the warning speed selected; and said selectorincludes a knob that is(a) moveable, at any time, to an "On" positionfor activating said system, and to an "Off" position for de-activatingsaid system, (b) operable in said "On" position to select the desiredspeed, (c) operable in said "On" position, while the car is in motion,to change the selected speed; and (d) operable to cause the selectedspeed to be shown on said warning speed display.
 2. The automobileoverspeed warning system of claim 1 wherein said annunciator includes atleast one of(a) a voice message generator; (b) a musical messagegenerator; and said warning system is connected to a loudspeaker of anexisting audio system of the car whereby said loudspeaker is drivable bysaid warning system to give the warning.
 3. The automobile overspeedwarning system of claim 1 wherein said knob is translatable along anaxis to activate said system, and rotatable about said axis to selectsaid warning speed; and said knob is operable to change said selectedwarning speed while the car is in motion.
 4. The automobile overspeedwarning system of claim 1 wherein said system is in the form of aretro-fit kit.
 5. The automobile overspeed warning system of claim 1wherein said warning system includes a "warning system on" display forindicating when said warning system is "on".
 6. The automobile overspeedwarning system of claim 5 wherein said "warning system on" displayincludes an illumination element for illuminating said knob that is litwhen said knob is in said "on" position, and said display is mountableadjacent to a speedometer of the car.
 7. The combination of theautomobile overspeed warning system of claim 1 and a cruise controlsystem for the car, the cruise control system being operable at aselected cruise control speed, said cruise control system beinginterruptible to become inactive when the car undergoes braking, andsaid warning system being operable at a selected warning speed higherthan the cruise control speed.
 8. The combination of claim 7 whereinsaid automobile warning system and said cruise control share amicroprocessor.
 9. The combination of claim 7 wherein said annunciatorincludes at least one of(a) a voice message generator; (b) a musicalmessage generator; and said warning system is connected to aloudspeaker.
 10. The combination of claim 9 wherein said loudspeaker isa loudspeaker of an existing audio system of the car.
 11. Thecombination of claim 7, the car having a speedometer, wherein saidannunciator gives an audible warning, said overspeed warning systemincludes a visible indicator mountable adjacent to the speedometer forinforming the driver that said overspeed warning system is activated;and said display is also mountable adjacent to the speedometer.
 12. Thecombination of claim 11 wherein said warning system is connected to atleast one of (a) a radio speaker of the car; (b) a speaker of a compactdisc player installed in the car; and (c) a speaker of a cassette playerinstalled in the car.
 13. The combination of claim 12 wherein saidwarning system is connected to emit a pre-recorded voice message oversaid speaker.